Apparatus for speech communication between divers



March 2, 1965 c. ALINARI 3,172,076

APPARATUS FOR SPEECH COMMUNICATION BETWEEN DIVERS Filed March 7, 1965 4 Sheets-Sheet 1 r- I 7 4 5 l l/ i Fig.7 i a 6 I l I I I I I I l l l I I I I I I I l I I .I

March 2, 1965 c. ALINARI 3,172,076

APPARATUS FOR SPEECH COMMUNICATION BETWEEN DIVERS Filed March 7, 1963 4 Sheets-Sheet 2 Fig. 4.

March 2, 1965 c. ALINARI 3,172,076

APPARATUS FOR SPEECH COMMUNICATION BETWEEN DIVERS Filed March 7, 1963 4 Sheets-Sheet a c. ALINARI 3,172,076

APPARATUS FOR SPEECH COMMUNICATION BETWEEN DIVERS March 2, 1965 4 Sheets-Sheet 4 Filed March '7, 1963 Fig. 9

United States Patent 3,172,076 APPARATUS FOR SPEECH COMMUNICATION BETWEEN DlVERS Carlo Alinari, 4 Via Giusti, Turin, Italy Filed Mar. '7, 1963, Ser. No. 263,463 Claims priority, application Italy, Mar. 10, 1962,

1 Claim. (Cl. 340-4) This invention relates to apparatus for speech communication between divers.

An object of this invention is to provide an apparatus adapted to be worn by a diver for intercommunication by speech which is light and easy in construction, enables a plurality of divers to intercommunicate simultaneously.

A further object of this invention is to provide an intercommunication apparatus by which divers can communicate with an operator in a base boat.

With the above objects in view this invention provides an apparatus for speech intercommunication of a plurali-ty of divers, comprising two electrodes adapted to be immersed into the surrounding liquid medium in order to transmit thereto or pick up therefrom a modulated electric current, an electroacoustic transducer adapted to supply to the two electrodes said current and convert the picked up current to sound vibrations, a tight-sealed container enclosing the acoustic transducer, means for fastening the casing to the diver and means for holding the two electrodes in such mutually spaced relationship that during immersion a link interconnecting the electrodes is self-oriented in the direction which is most efficient for communication with other apparatus.

Further characteristic features and advantages of this invention will be understood from the appended detailed description referring to the accompanying drawings given by way of example, wherein:

FIGURE 1 is a diagrammatical view of the improved apparatus;

FIGURE 2 is an outer perspective view of the apparatus according to a first practical embodiment,

FIGURE 3 is a part sectional view of the apparatus along the arrow X in FIGURE 2;

FIGURE 4 is a diagrammatical view of the current lines in a liquid medium;

FIGURE 5 shows diagrammatically a mutual arrangement of the electrodes of an apparatus;

FIGURE 6 is a sectional view of a float carrying one of the electrodes;

FIGURES 7 and 8 show the manner of using the improved apparatus;

FIGURE 9 is an external view of a modified embodiment.

Referring to FIGURES 1 to 6, two electrodes 1, 2 each comprise two metal plates adapted to be immersed into the surrounding liquid in order to transmit thereto a modulated electric current or pick up said current therefrom.

The electrodes 1, 2 are electrically connected through an amplifier quadripole 4 to a loud-speaker microphone 3.

The loud-speaker microphone and amplifier quadripole 4 form together an electro-acoustic transducer capable of converting sound energy to electric energy and vice versa.

Referring to FIGURE 1 which shows the apparatus ready for transmission, the electrodes 1, 2 are electrically connected to two terminals 5, 6, respectively of the quadripole 4 and leads 19a, 19b of the loud-speaker microphone 3 are electrically connected to the other two terminals 7, 8, respectively of the quadripole 4.

A change-over switch 9a, 9b effects change over from transmission to reception. In the latter condition the electrode 1 is connected to terminal 7, the lead 19a from ice the loud-speaker microphone 3 being connected to terminal 5.

The receiving condition of the change-over switch 9a, 9b is shown by dot-and-dash line in FIGURE 1.

As shown in FIGURES 2 and 3, a container 12 provided with a tight-sealing cover plate 13 encloses all component parts of the apparatus, exclusive of the electrodes 1 and 2.

The container 12 is provided with straps 21 for fastening the apparatus to a part of the divers body, preferably his head in proximity to one ear.

As shown in FIGURE 3, the ear-piece of the loudspeaker microphone 3 is secured to the cover plate 13 which is tightly sealed to the opening of the container 12 by means of a screw 15, the head 17 of which sealingly extends from the bottom of the container 12, the screw shank being engaged by a tapped blind hole in the body of the loud-speaker microphone 3.

A packing 13a of an elastomer, such as neoprene is interposed between the container 12 and cover plate 13 for sealing purposes and extends to overlap the cover plate 13 in order to cover any discontinuity in the plate, FIGURE 3.

One electrode, 2, is secured to the container 12 by means of insulating grommets 2a; the other electrode, 1, is secured to a float 11.

A member 15 of line form, flexible in part at least has its ends secured to the float 11 and container 12, respectively.

During immersion the float 11 stretches the line 10 thereby tending to maintain the electrodes 1, 2 vertically spaced.

The line 16 preferably comprises a braided lead 10a electrically interconnecting the electrode 1 and electroacoustic transducer, and an insulating coating 1%, FIG- URE 6.

The float 11 comprises a body of a lower specific weight than the liquid medium, such as of closed-cell foamed plastics, having externally secured thereto an electrode 1, as shown in FIGURE 6.

As shown in FIGURES 2 and 3 an operating lever 15 for the change-over switch 9a, 9b and a switch 14 extend from the container 12, the switch 14 cutting in and oif, respectively, the electric batteries (not shown) energizing the transducer circuit.

The operation of the apparatus shall now be described with reference to FIGURES 4 and 5.

A and B denote the positions occupied in the liquid medium by the two electrodes of an apparatus arranged for transmission of speech.

A potential diiference variable with a speech frequency between the locations A, B generates in the surrounding medium an electric current variable according to the same law as the potential difference between A and B.

Along the lines 18 of current, falls in potential occur due to the electric resistivity of the liquid medium.

C, D denote the positions of two electrodes of an apparatus arranged for reception.

The fall in potential between C, D, which amounts to a fraction of the diiference in potential between A, B is amplified by the apparatus arranged for reception and converted to sound energy in the transducer.

Similarly, a potential difference exists between E, F due to the variation in electric field between these two locations, and can be picked up by an apparatus arranged for reception, the electrodes of which are situated at E, F.

Since distribution of the lines of current is as indicated in the diagram of FIGURE 4, no appreciable potential diiierence exists between two such points as M, N situated on a straight line extending through A, B. Consequently, by placing two electrodes of an apparatus an arranged for reception at N, M, no signal can be received.

No reception is possible either if the two electrodes of an apparatus arranged for reception are situated at two equipotential locations, such as L and I in FIGURE 5.

L, I are equally spaced from the location A, B of the electrodes of an apparatus arranged for transmission.

The intensity in reception depends upon the orientation of the link interconnecting the electrodes of the receiving apparatus with respect to the link interconnecting the electrodes of the transmitting apparatus.

The condition affording highest etficiency in speech is attained when the links interconnecting the two electrodes of the various apparatus extend in a parallel relationship.

Parallelism is constantly afforded by the apparatus according to this invention. When the divers stand still as shown in FIGURE 7, the electrodes 1, 2 of the various apparatus self-arrange themselves with their links upright and mutually parallel.

If the divers swim in company, as shown in FIGURE 8, the resistance opposed by the medium causes the links to incline still in a mutually parallel relationship.

FIGURE 7 diagrammatically shows a manner of maintaining the electrodes 11, 2 of an apparatus in a spaced oriented condition, which is particularly useful when the apparatus is Worn by an operator in a base boat 2t) for the divers.

A link 10, which is flexible in part at least, has its ends fastened to the two electrodes 1, 2, respectively, one of which has secured thereto a ballast 22.

A suspension line 26 is secured at its ends to the other electrode and container 12, respectively, of an apparatus worn by an operator on board a boat 20.

The link 19 and suspension line 26 each comprise an electric lead interconnecting one electrode and the electroacoustic transducer respectively and a dielectric coating insulating it from the other lead and surrounding liquid medium.

The link 10 and suspension line 26 each comprise a flexible bipolar cable.

FIGURE 9 is an outer view of an embodiment of this invention, which is especially convenient in fastening the apparatus to a diver and replacing the electric batteries.

The container comprises two capsules 27, 28 including tight-sealing covers 29, 30.

The capsules 27, 28 enclose the electro-acoustic transducer and electric batteries feeding the transducer, respectively.

A lever 15 extends from capsule 27 and operates the lchange-over switch within the capsule, an operating lever 14 extending from capsule 28 for switching in and off the batteries feeding the transducer.

The capsules 27, 28 are interconnected by a bowed flexible metal strip 31 carried by grommets 31a.

The strip 31 acts as one of the electrodes on the apparatus and is electrically connected to the electro-acoustic transducer.

The other electrode denoted by 32 is secured to a float 33 and is electrically connected to the electro-acoustic transducer by means of a fiexible link 23 consisting of a flexible cable comprising an insulated braided lead 34.

According to this modification the apparatus takes the form of a headphone and is fastened to the divers head by means of a strap 35 extending around his throat.

I claim:

Apparatus for speech communication between divers, and adapted to be fastened to a divers body, said apparatus comprising:

a container;

a cover plate sealingly secured on said container to form a watertight closure therewith, said cover plate having an inner side facing said container and an outer side facing away from said container;

a first isolated electrode externally fixed to said container;

a second isolated electrode;

a flexible link connecting said second electrode to said container;

an amplifier circuit electrically connected between said first and second electrodes and comprising a loudspeaker having a rigid body formed with an earpiece, said earpiece being connected to the inner side of said cover plate; and

means for fastening said container on a divers body with the outer side of said cover plate being disposed adjacent one of the divers ears.

References Cited by the Examiner UNITED STATES PATENTS 1,051,443 1/ 13 Pickard 340-4 1,197,366 9/16 Hahnemann 3404 2,538,419 1/51 Huston et al.

3,003,136 10/61 Burnett 340--5 3,076,174 1/63 Wainwright et al. 3405 CHESTER L. JUSTUS, Primary Examiner. 

